Most copy number amplification events occur in the FGFR1 gene [49], being associated with several cancers, particularly breast cancers, to which they indicate poor prognosis and recurrence, and FGFR4 genes [56], but they are also present in other family members, with those of FGFR2 gene being found in gastric and breast tumors [57,58]. Here, FGFR4 is linked to breast carcinoma.